The 2010/2011 snow season in California’s Sierra Nevada: Role of atmospheric rivers and modes of large-scale variability

American Geophysical Union (AGU) | October 17th, 2013

The anomalously snowy winter season of 2010/2011 in the Sierra Nevada is analyzed interms of snow water equivalent (SWE) anomalies and the role of atmospheric rivers (AR

The anomalously snowy winter season of 2010/2011 in the Sierra Nevada is analyzed interms of snow water equivalent (SWE) anomalies and the role of atmospheric rivers (ARs)—narrow channels of enhanced meridional water vapor transport between the tropics and extratropics. Mean April 1 SWE was 0.44 m (56%) above normal averaged over 100 snow sensors. AR occurrence was anomalously high during the period, with 20 AR dates during the season and 14 in the month of December 2010, compared to the mean occurrence of nine dates per season. Fifteen out of the 20 AR dates were associated with the negative phases of the Arctic Oscillation (AO) and the Pacific-North American (PNA) teleconnection pattern. Analysis of all winter ARs in California during water years 1998–2011 indicates more ARs occur during the negative phase of AO and PNA, with the increase between positive and negative phases being90% for AO, and50% for PNA. The circulation pattern associated with concurrent negative phases of AO and PNA, characterized by cyclonic anomalies centered northwest of California, provides a favorable dynamical condition for ARs. The analysis suggests that the massive Sierra Nevada snowpack during the 2010/2011 winter season is primarily related to anomalously high frequency of ARs favored by the joint phasing of AO and PNA, and that a secondary contribution is from increased snow accumulation during these ARs favored by colder air temperatures associated with AO, PNA, and La Nina.

The 2014 Sustainable Groundwater Management Act: A Handbook to Understanding and Implementing the Law

Water Education Foundation | January 1st, 2015

This handbook provides crucial background information on the Sustainable Groundwater Management Act, signed into law in 2014 by Gov. Jerry Brown. The handbook also includ

This handbook provides crucial background information on the Sustainable Groundwater Management Act, signed into law in 2014 by Gov. Jerry Brown. The handbook also includes a section on options for new governance as well as chapters on SGMA fees and case studies of SGMA implementation. Background information in the handbook provides an overview of California groundwater and the SGMA, a timeline and a list of frequently asked questions. The chapter on approaches and options for governance explains how a Groundwater Sustainability Agency might be formed and what the broad goals of a Groundwater Sustainability Plan. Also included is an easy-to-understand definition of the three options for governance and a step-by-step guide with tips on forming a GSA. This handbook was developed with funding from the California Water Foundation.

The 2025-26 Budget: Proposition 4 Spending Plan

Legislative Analyst's Office (LAO) | February 12th, 2025

The Agricultural Significance of Sunshine as Illustrated in California

National Oceanic and Atmospheric Administration (NOAA) | September 4th, 1919

The Ahwahnee Water Principles

Local Government Commission | July 1st, 2006

In 2004,the Local Government Commission set out to identify effective,least-cost economically and politically viable options for sustainable water resources management at

In 2004,the Local Government Commission set out to identify effective,least-cost economically and politically viable options for sustainable water resources management at the local level. The LGC invited respected water resource policy, management and planning professionals – with experience at the federal,state and local levels – to craft a set of land use principles which would provide guidance to local officials and communities concerned about sustaining future water supplies. The process of developing the Ahwahnee Water Principles mirrored the LGC’s earlier Ahwahnee Principles for Resource-Efficient Communities, which were released in 1991. The Ahwahnee Principles presented a blueprint for elected officials to create compact, mixed-use,walkable,transit-oriented developments in their local communities,and have since paved the way for growing acceptance and inclusion of “smart growth”and the “New Urbanism”in local and regional land-use policies and practices.

The Alkaline and Boracic Lakes of California

Scientific American | July 7th, 1877

Immediately east of the range of the Sierra Nevada is an extensive region of alkaline lakes and hot springs, of which very large areas are almost totally barren, the onl

Immediately east of the range of the Sierra Nevada is an extensive region of alkaline lakes and hot springs, of which very large areas are almost totally barren, the only vegetation consisting of wild sage, yucca, a few cacti, and scanty tufts of bunch-grass. This district affords, in its many extensive craters and in its lavas, basalts, and obsidians, the most conclusive evidence of its volcanic origin, while its solfataras and boiling springs may be regarded as the last representatives of active volcanicity. Although this region is one of great scientific interest, and may eventually become industrially important, it appears to be but little known in this country, and it has therefore been thought that a brief description of the district, as well as that of the borax lakes, lying on the western side of the Sierra, might not be without interest to English readers. The most remarkable of the alkaline lakes of this portion of California are Mono and Owens Lakes.

The Anatomy of a Drought in the Upper San Francisco Estuary: Water Quality and Lower-Trophic Responses to Multi-Year Droughts Over a Long-Term Record (1975-2021)

University of California, Davis (UC Davis) | December 23rd, 2024

The Ancient Lakes of Western America, their Deposits and Drainage

Nature Portfolio (Springer Nature) | September 8th, 1870

By continental elevation the whole country west of the Mississippi was raised out of the cretaceous sea, and these estnaries became lakes inclosed by raised dry land. The

By continental elevation the whole country west of the Mississippi was raised out of the cretaceous sea, and these estnaries became lakes inclosed by raised dry land. The knowledge of this country from the Mississippi to the Pacific Ocean has been accumulated by various explorers besides the writer, as Dr. Hayden, Mr. George Gibbs, Professors W. P. Blake and Thomas Antisell, and Prof. J. D. Whitney and the State Geological Survey of California, and Baron Richtofen, the lamented Rémond, Drs. Shiel, Wislizenus, and others. Besides Mr. Clarence King has explored a large tract of this country, but his very important contributions have not, as yet, been made public. The general character of the topography of the region west of the Mississippi has been given by these great lines of elevation traversing the country from north to south. There are the Rocky Mountains, the Sierra Nevada, and the Coast Ranges. The last is the most modern, and is composed, for the most part, of Miocene Tertiary rocks. Parallel with this lies a narrow trough, in California traversed by the Sacramento and San Joachin Rivers, encroached on by the mountains at places, but still in Oregon and Washington, traversed by the Willamette and Cowletz Rivers. These two sections are drained through the Golden Gate and Columbia.

The Application of Ground-Water Flow Models as Predictive Tools—A Review of Two Ground-Water Models of Eastern Honey Lake Valley, California-Nevada

Geological Society of America (GSA) | January 9th, 1992

In the late 1980's Washoe County, Nevada, entered into an agreement with a private water development company to develop and export groundwater from the Nevada portion of

In the late 1980's Washoe County, Nevada, entered into an agreement with a private water development company to develop and export groundwater from the Nevada portion of the arid Honey Lake Valley to the rapidly growing Reno-Sparks area. The proposed project is known as the Truckee Meadows Project (TMP). Honey Lake Valley is 35 mi north of Reno, Nevada; but is located predominantly in California. Computer groundwater models of the valley were prepared by the USGS and the TMP proponents and presented to the Nevada State Engineer to evaluate the impacts of the proposed exportation of 15,000 ac-ft annually from eastern Honey Lake Valley. By using assumptions, numbers, and data which are not justified by the scientific data, both models place unreasonable and, in some instances, artificial constraints on the geology and hydrogeology of the groundwater system rather than allowing the geology and hydrogeology to constrain the models. Neither model is useful as a predictive tool. However, the major problems with the two models fall into two fundamentally different classes. The USGS model exceeded the technical limitations of the model code and made large, inappropriate adjustments to the water budget to compensate for these undetected errors. The TMP model used a water budget that was not technically justified or explained and placed the spatial distribution of ground-water recharge and discharge beyond the realm of hydrogeologic reality.  

The approaching obsolescence of 137Cs dating of wetland soils in North America

Quaternary Science Reviews (Elsevier) | September 24th, 2018

The peak fallout in 1963 of the radionuclide 137Cs has been used to date lake, reservoir, continental shelf, and wetland sedimentary deposits. In wetlands such dating is

The peak fallout in 1963 of the radionuclide 137Cs has been used to date lake, reservoir, continental shelf, and wetland sedimentary deposits. In wetlands such dating is used to project the ability of wetlands to keep pace with sea level rise and develop strategies for mitigating carbon pollution using biological carbon sequestration. Here we demonstrate that reliable 137Cs profiles are increasingly difficult to obtain from wetland soils. Among 58 soil cores recently collected from a range of wetland types and 137Cs fallout densities across the United States, 25% contain no identifiable 137Cs peaks. Less than 40% of 137Cs ages are consistent with 210Pb dating. We provide a new measure of 137Cs peak clarity (t) for our core dataset by comparing the 50% interquartile range of data around the 137Cs peak for “ideal” cores profiles determined using 137Cs fallout data to that of observed core profiles. Our results show that overall t is approximately 10 times greater for observed cores than ideal cores. The deterioration in the 137Cs peak has occurred due to radionuclide decay, 137Cs migration in situ, which is ubiquitous in this study, and 137Cs amendments from surface waters. Such deterioration likely extends to both Mexican and non-permafrost, Canadian wetlands. We recommend continued use of 137Cs only if the full bound of dating uncertainty for both 137Cs and an additional method such as 210Pb is propagated into estimates of wetland vertical accretion and carbon sequestration.